String Sorter

sort_string.cpp

#define _CRT_SECURE_NO_WARNINGS
#include <fstream>
#include <iostream>
#include <string>
#include <algorithm>
#include <unordered_set>
#include <chrono>
#include<iostream>

using namespace std;

//8976
//118374

//when avoid copy 
//9159 in length_sort
//30182
//#define VECTOR
#ifdef VECTOR
vector <std::string> words(10000);
bool length_sort(string &x, string &y){
	const size_t lhsLength = x.length();
	const size_t rhsLength = y.length();
	if(lhsLength==rhsLength)
		return x<y;
	return lhsLength < rhsLength;
}

void ReadFile(string filename){
	string line;
	
	std::ifstream infile(filename);
	while (getline(infile, line))
	{
		words.push_back(line);
	}
	infile.close();
}
#else
char *buffer;
char ** words;
long wcnt;
void ReadFile(char *filename){
	FILE * fp=fopen(filename,"rb");
	long sz;
	//get the size of file
	fseek(fp, 0L, SEEK_END);
	sz = ftell(fp);
	fseek(fp, 0L, SEEK_SET);
	buffer=(char*)malloc(sz*sizeof(char)+10);
	fread(buffer,sizeof(char),sz,fp);	
	fclose(fp);
	long cnt=0;
	for(long i=0;i<sz;i++){
		if(buffer[i]=='\n'){
			buffer[i]='\0';
			cnt++;
		}
	}
	words=(char **) malloc(sizeof(char*)*cnt);
	words[0]=&(buffer[0]);

	wcnt=cnt;
	cnt=1;
	for(long i=1;i<sz;i++){
		if(buffer[i]=='\0'){
			words[cnt++]=&(buffer[i+1]);
		}
	}
}
bool length_sort(char * x, char * y){
	const size_t lhsLength = strlen(x);
	const size_t rhsLength = strlen(y);
	if(lhsLength==rhsLength)
		return strcmp(x,y)<=0;
	return lhsLength < rhsLength;
}

#endif
void main(){

	auto begin = chrono::high_resolution_clock::now(); 
	ReadFile("C:/data/words.txt");
	auto end = chrono::high_resolution_clock::now();    
	auto dur = end - begin;
	auto ms = std::chrono::duration_cast<std::chrono::milliseconds>(dur).count();
	cout << ms << endl;
#ifdef VECTOR
	sort(words.begin(),words.end(),length_sort);
#else
	sort(words,words+wcnt,length_sort);
#endif
	end = chrono::high_resolution_clock::now();    
	dur = end - begin;
	ms = std::chrono::duration_cast<std::chrono::milliseconds>(dur).count();
	cout << ms << endl;
	int a;
	cin >>a;
}